Wind tower erection system

ABSTRACT

Tall wind towers can be erected using a mobile tilting frame comprising a major gin pole and a minor gin pole having a longitudinal axis. The tilting frame has a support cable connecting the major/minor gin poles. The minor gin pole can pivot relative to the major gin pole so that the longitudinal axis of the minor gin pole can be perpendicular to the longitudinal axis of the major gin pole.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present Application is divisional of U.S. patent application Ser.No. 14/632,757, titled “Wind Tower Erection System,” filed Feb. 26,2015, which claims the benefit of U.S. Provisional Patent ApplicationNo. 61/945,619, titled “Wind Tower Erection System,” filed Feb. 27,2014, the contents of which are incorporated herein by reference intheir entirety.

BACKGROUND

Wind towers are effective in harnessing energy without consumption offossil fuels. Generally the taller the wind tower the more efficient itis. Typically, wind towers are 60-80 meters in height.

It is desirable for efficiency to have taller wind towers. However, as awind tower gets taller, it is necessary that the base be of largerdiameter. The diameter of a wind tower base is limited when the windtower is manufactured off site by freeway underpass clearances. Atlarger diameter bases, it is not practical to transport the base portionof a wind tower by truck through a highway system.

Another limit on the height of wind towers is the size of a cranenecessary to erect the wind tower on site.

Technology is being developed so that a wind tower of increased heightcan be constructed on site so that the transportation limit on windtower size can be avoided. For example, see Keystone U.S. PatentPublication Nos. 2011/0179623 and 2013/0074564. However, there remainsthe challenge of erecting a tall wind tower, particularly when theheight is 100 meters or higher. Moreover, with very tall wind towers itis difficult to repair or replace the turbine, or major components suchas bearings, rotors, and blades and upper portion of the wind tower. Itis expensive to bring in a crane to access the top of a tall wind tower,even if such a crane is available. Although minor repairs can be made bya worker climbing the wind tower, if it is necessary to completelyreplace the turbine or blades or upper portion of the tower, that is notpractical for very high wind towers, and the investment in the windtower can be lost. Current technologies to build or assemble highertowers on site and in position exists (cast in place concrete, precastconcrete components, slip forming); however, these methods are too slowand expensive to achieve the desired economic viability to make windenergy economical.

Accordingly, there is a need for a system for erecting and repairingtall wind towers on site.

SUMMARY

The present invention provides a system that satisfies this need. Thesystem includes a method for erecting a wind tower having turbine and atleast one blade. A preferred method can comprise the following steps,not necessarily in the order presented:

-   -   p A. Building a foundation for the wind tower;    -   B. Providing a pivot base for the wind tower; and    -   C. Providing a wind tower support structure. Preferably the        support structure is made on site, but it can be made off site.        The support structure has a longitudinal axis substantially        parallel to the ground, the support structure having a base        section and a distal turbine section for supporting the turbine        and blade.

The method can include the following additional steps:

-   -   D. Attaching the base section of the wind tower to a pivot base        so that the support structure can be pivoted to a vertical        position;    -   E. Attaching the turbine and the blade to the distal section of        the support structure;    -   F. Moving a mobile tilting frame proximate to the pivot base and        connecting the tilting frame to the pivot base, the tilting        frame comprising a major gin pole having longitudinal axis and a        minor gin pole having a longitudinal axis. The tilting frame has        a first support cable connecting the major and minor gin poles.        The minor gin pole optionally can pivot relative to the major        gin pole;    -   G. Connecting the minor gin pole to an anchor with a second        support cable. The anchor can be an anchor formed for this        purpose, or can be the foundation of another wind tower as part        of a wind tower farm;    -   H. Tilting the tilting frame so that the major gin pole is        substantially vertical, wherein the longitudinal axis of the        minor gin pole is at an angle relative to the longitudinal axis        of the major gin pole;    -   I. Securing at least one tilting cable to the major gin pole and        the tower support structure and thereafter pivoting at least a        portion of the wind tower to a substantially vertical        orientation using the tilting frame;    -   J. Locking the wind tower in its substantially vertical        position;    -   K. Disconnecting the tilting cable from the major gin pole and        pivoting the tilting frame to a position so that the        longitudinal axis of the tilting frame major gin pole is        substantially parallel to the ground; and    -   L. Moving the tilting frame away from the pivot base.

The invention also includes the mobile tilting frame itself and usingthe tilting frame for lowering a wind tower for repair or replacement ofparts.

In one method of the invention, one can secure a pivot base to thesupport structure, the foundation, or a separate foundation.Furthermore, in step (E) the turbine and blade can be attached before orafter tilting of the tilting frame of step (H). The base section can beattached pivotally with a pivot pin. The wind tower can be locked intoplace with either a pin or bolts. The method of the invention can beused to erect towers at least 150 meters tall. Furthermore, cables canbe attached to the tower and support structure to stabilize thesestructures. Lastly, the method can be reversed to easily tilt the towerdown for major turbine repairs, rebuild, replacement and upgrades.

Furthermore, the method can comprise the use of more than one major ginpole for very high towers. This configuration comprises at least a firstand second major gin poles each having a longitudinal axis; a minor ginpole having a longitudinal axis; a first support cable connecting thefirst major gin pole and the minor gin pole; and a second support cableconnecting the first and second major gin poles. In one aspect, thesecond major gin pole is greater in length than the first major ginpole, and each additional major gin pole is longer than the precedinggin pole, i.e., major gin pole 4 is longer than major gin pole 3 whichis longer than major gin pole 2. In this configuration, the tilting ofthe tilting frame and erection of the wind tower is accomplished in thesame manner as described above for a two-stage gin pole configuration.

DRAWINGS

These and other features, aspects, and advantages of the presentinvention will become better understood with regard to the followingdescription, the features specified below, and the accompanying drawingswhere:

FIGS. 1-16 schematically demonstrate a preferred method of erecting awind tower according to a system having features of the presentinvention, wherein the steps need not necessarily be performed in theorder shown in the figures and not all of the steps need be performed.

DESCRIPTION

A system according to the present invention is particularly useful forerecting tall wind towers and is described in detail for that purpose.However it can be used for other applications such as erecting antennas,oil drills and other tall, elongated, relatively narrow structures.

As shown in FIG. 16, a conventional wind tower 20 comprises an elongatedsupport structure 22 having a base section 24 and a distal turbinesection 26 on which is mounted a turbine 28 with blades 30. A typicalwind tower is about 60-80 meters in height, and the present inventioncan be used with conventional wind towers. However, the invention isparticularly useful for tall wind towers, such as those 150 meters andtaller, particularly wind towers 180 meters and taller. The base section24 for such tall towers is typically from about 5 meters to 10 meters indiameter or larger.

With reference to FIG. 1, a foundation 32 for the wind tower 20 isformed in a. conventional manner. Typically, at least a portion of thefoundation 32 is below ground level. Thereafter, as shown in FIG. 2, apivot base 34 is secured to the foundation 32. Optionally, the pivotbase 34 can be built into the support structure 22. The pivot base 34preferably is provided with multiple holes, schematically represented bya single hole 36, for receiving a pivot pin 37 (FIG. 5) and one or morelocking pins as described below.

With reference to FIG. 3 an anchor 38 is provided. Optionally the baseor foundation of another wind tower can be used as an anchor.

With reference to FIG. 4, the support structure 22 is initially providedoriented parallel, or close to parallel, to the ground and supported bysupport brackets 39 or the like. The support structure 22 can befabricated on site, can be fabricated off site and transported to theerection site, or can be fabricated in segments fabricated off site andtransported to the erection site and assembled on site. Preferably thesupport structure 22 is formed on site with a machine 42 such as usingthe technology described in the aforementioned Keystone published patentapplications. The elongated support structure 22 has a longitudinal axislabelled as reference number 44 in FIG. 4.

As shown in FIG. 5, the base section 24 of the support structure 22 issecured to the pivot base 34 using a pivot pin (not shown), so that thesupport structure 22 can be pivoted to a vertical position.

As shown in FIG. 6, the turbine 28 and blades 30 are then secured to thedistal section 26 of the support structure 22. This step need not beperformed in this sequence, in that the turbine and blade can beinstalled prior to attachment of the support structure to the pivot baseor after some of the following steps. Preferably the turbine 28 andblades 30 are secured to the support structure 22 while the supportstructure 22 is easily accessible by being substantially parallel to theground. However they can be secured after the support structure 22 istilted to its vertical position or during the tilting process.

As shown in FIG. 7, a mobile tilting frame 46 is moved proximate to thepivot base 34, the frame 46 typically being supported on and moved intoplace on dollies 47 or straddle cranes. The mobile tilting frame 46 canhave its own built-in wheels rather than rely on separate dollies 47 formovement.

The mobile tilting frame 46 comprises a major gin pole 48 and a minorgin pole 50 connected by at least one, and preferably a plurality offirst support cables 52 where one end of the support cables is attachedto a first end 54 of the minor gin pole 50 and the other end of thesupport cables 52 is attached to the major gin pole 48 at a locationbetween its ends. The minor gin pole 50 is used to tilt up and stabilizethe major gin pole 48, and the major gin pole 48 is used to tilt up andstabilize the tower (FIG. 8). A second end 56 of the minor gin pole 50is pivotally secured to the end of the major gin pole 48 that isproximate to the pivot base 34. Generally, the longitudinal axis of theminor gin pole 50 is perpendicular to the longitudinal axis of the majorgin pole 48, although that angle 58 (see FIG. 8) can be from about 45degrees to about 120 degrees. The tilting frame 46 is secured to thepivot base 34 so that it can be pivoted so that the major gin pole 48can be substantially vertical.

The term “mobile” means a structure that is capable of being movedreadily and is not a portion of the wind tower structure or thefoundation structure.

The length of the major gin pole 48 is typically about 10% to about 50%,and preferably about 15% to about 25% of the length of the supportstructure 22. The length of the minor gin pole 50 is typically about 10%to about 50% of the length of the major gin pole 48.

With reference to FIG. 9, the minor gin pole 50 is secured to the anchor38 with a second support cable 52, and typically multiple cables.Wherever a cable is referred to herein, generally multiple cables areused, both to provide increased strength, and also to prevent undesiredtilting of the structures to which the cables are attached.

As shown in FIG. 10, the mobile tilting frame 46 is then tilted so thatthe major gin pole 48 is substantially vertical, or can even be tiltedbeyond the vertical position. Tilting is effected with a tilting powersystem typically comprising a winch and a motor for driving the winch(not shown). The tilting power system can comprise hydraulic jacks, or awinch and motor in combination with hydraulic jacks. The tilting powersystem can be part of the mobile tilting frame 46, or it can be aseparate structure such as being placed by the anchor 38. Stabilizingcables 60 are used to secure the tilting frame 46.

As shown in FIG. 11, the major gin pole 48 is connected to the supportstructure 22 by a plurality of tilting cables 59. Generally the tiltingcables 59 are secured to the top of the major gin pole 48, before it istilted to its vertical position, at anchor points 57 which can beterminal anchor points or sheared anchor points. There can be a singleanchor point or multiple anchor points. Then the free ends of thetilting cables 59 can then be attached, after the tilting frame istilted, to the support structure 22. These cables could alternately beconnected to structure 22 prior to the tilting of major gin pole 48(FIG. 12).

The tilting rigging/cables and the stabilizing rigging/cables work intandem to safely tilt the tower up and keep it from falling over untilthe bottom connection is secured.

As demonstrated in FIGS. 11A-C, the tilting frame can have more than asingle major gin pole, such as at least a first major gin pole 48 and asecond major gin pole 48B. Furthermore, the gin pole configuration canbe increased to a 3, 4, . . . , X stage gin pole tilting frame system toaccommodate very high towers. Typically, each additional major gin pole48B is longer than the first major gin pole 48. To erect the secondmajor gin pole 48B, the tilting frame is tilted so that the longitudinalaxis of the first major gin pole 48 is no longer substantially verticaland the longitudinal axis of the second major gin pole 48B is vertical.As depicted in FIG. 11B, each first major gin pole 48 is attached by asupport cable 52 to an anchor and by a tilting cable 59 to the secondmajor gin pole 48B. Stabilizing cables 60 support the first major ginpole 48. As demonstrated in FIG. 11C, after the last major gin pole 48Bis raised vertically, the last major gin pole 48B is connected to thesupport structure 22 by a plurality of tilting cables 59 in the samemanner the tilting cables 59 are connected to major gin pole 48. In themulti-major gin pole configuration, the support structure 22 is tiltedto a vertical position in the same manner described below.

As demonstrated by FIGS. 12 and 13, again using a tilting power system(not shown), the support structure 22 is tilted to a vertical position,where it is secured in place, such as through use of one or more lockingpins extending through the support structure and the pivot base 34,and/or can be secured with bolts or the like. It is also possible toweld it in place, but preferably that is not done, so that the tower canbe tilted downwardly to a horizontal position for repair/or replacingthe components. The gin poles can be tilted to any angle between 9 and12 o'clock, i.e., vertical or beyond vertical by 90 degrees, during thetilting of the tower.

The hinged bottom section of the tower can consist of a double pinnedconnection. A first pin is used as a rotation point during the tiltingof the tower while a second pin is inserted after the tower is tilted tothe vertical position and is used to fasten and secure the tower.Alternatively, the tower can be rotated on one offset pin and the hingedsection can be fastened and secured using a conventional boltedconnection after the tower is tilted to its vertical position.

As shown in FIG. 14, the tilting frame 46 is then released from thevertical wind tower and tilted so that the major gin pole 48 issubstantially parallel to the ground. Then the mobile tilting frame, asshown in FIG. 15, can be moved to another location for storage or forerecting another wind tower or repairing another wind tower. The twostage gin pole tilting frame assembly can be relocated withoutdismantling it. The relocation can be done using lifting equipment,straddle cranes, crawler carriers, heavy hauler, SPMT (self-propelledmodular transporters) or by towing. The tilting frame can also berelocated under its own power, such as by utilizing a power pack andgenerator to propel steerable wheels.

An advantage of using this technique for erecting a wind tower with amobile tilting frame is that the wind tower can easily be tilted back toa substantially horizontal position so that the blades, turbine, and/ortop portion of the support structure can be repaired or replaced. Thisis effected by moving the mobile tilting frame 46 proximate to thefoundation 32, connecting the minor gin pole 50 to the anchor 38 (whichcan be the foundation 53 (FIG. 9) of another wind tower), and thentilting the tilting frame so that the major gin pole 48 is substantiallyvertical and the longitudinal axis of the minor gin pole 50 is at anangle relative to the longitudinal axis of the major gin pole 48 of fromabout 45 degrees to 90 degrees. Then at least one tilting cable can besecured to the major gin pole 48 and the tower support structure, andusing the tilting frame 46, the wind tower can be pivoted to anorientation substantially parallel to the ground.

A system according to the present invention has significant advantagesover conventional techniques for erecting a wind tower. The mobiletilting frame can be reused for multiple wind towers, helping todecrease cost. Large cranes are not required. Also the system can beused for erecting towers substantially taller than conventional windtowers.

The invention has numerous other advantages over the prior art. Towerscan be erected quickly due to the easy and rapid relocation process. Thesystem can be scaled up and down to accommodate different tower heights.The system can be increased to multiple major gin poles in the tiltingframe system to accommodate higher towers, specifically for erection oftall towers (over 150 meters). Furthermore, the method of the presentinvention allows for a lower overall project cost when compared to theprior art. Lastly, the method can be reversed to easily tilt the towerdown for major turbine repairs, rebuild, replacement and upgrades.

Although the present invention has been described with a degree ofparticularity, it is understood that the present disclosure has beenmade by way of example and that other versions are possible. As variouschanges could be made in the above description without departing fromthe scope of the invention, it is intended that all matter contained inthe above description or shown in the accompanying drawings shall beillustrative and not used in a limiting sense. The spirit and scope ofthe appended claims should not be limited to the description of thepreferred versions contained in this disclosure.

All features disclosed in the specification, including the claims,abstracts, and drawings, and all the steps in any method or processdisclosed, may be combined in any combination, except combinations whereat least some of such features and/or steps are mutually exclusive. Eachfeature disclosed in the specification, including the claims, abstract,and drawings, can be replaced by alternative features serving the same,equivalent or similar purpose, unless expressly stated otherwise. Thus,unless expressly stated otherwise, each feature disclosed is one exampleonly of a generic series of equivalent or similar features.

Any element in a claim that does not explicitly state “means” forperforming a specified function or “step” for performing a specifiedfunction should not be interpreted as a “means” or “step” clause asspecified in 35 U.S.C. §112.

What is claimed is:
 1. A tilting frame suitable for erecting a windtower comprising a major gin pole having a longitudinal axis and a minorgin pole having a longitudinal axis, the tilting frame having a firstsupport cable connecting the major and minor gin poles and wherein thelongitudinal axis of the minor gin pole can pivot relative to thelongitudinal axis of the major gin pole at an angle of from about 45 toabout 120 degrees.
 2. The tilting frame of claim 1, further comprisingat least two major gin poles.
 3. The tilting frame of claim 1, whereinthe major gin pole is longer than the minor gin pole.
 4. The tiltingframe of claim 1, wherein the minor gin pole is 10% to 50% of the lengthof the major gin pole.
 5. The titling frame of claim 1, wherein theminor gin pole can pivot relative to the major gin pole so that thelongitudinal axis of the minor gin pole is at an angle relative to thelongitudinal axis of the major gin pole of from about 45 to about 120degrees.
 6. The tilting frame of claim 1, further comprising a secondsupport cable, for securing the tilting frame to an anchor.
 7. Thetilting frame of claim 1, wherein the tilting frame is mobile.
 8. Thetiling frame of claim 1, wherein the minor gin pole can pivot relativeto the major gin pole so that the longitudinal axis of the minor ginpole can be perpendicular to the longitudinal axis of the major ginpole.
 9. The tilting frame of claim 1, wherein the tilting frame furthercomprises a power system to tilt the major gin pole and minor gin pole.10. A combination comprising: (a) the tilting frame of claim 1; and (b)a wind tower comprising an elongated support structure, a turbine, andat least one blade on a surface, the support structure being attached toa foundation having a pivot base.
 11. The combination of claim 10,wherein the tilting frame is positioned proximate to the pivot base andconnected to the pivot base.
 12. The combination claim 10, wherein thepivot base is built into the foundation.
 13. The combination of claim10, wherein the pivot base is secured to a second foundation separatefrom the wind tower foundation.
 14. The combination of claim 10,comprising a power system for pivoting at least a. portion of the windtower into position.
 15. The combination of claim 10, wherein the windtower is locked into a substantially vertical position relative to theground.
 16. The combination of claim 10, wherein the wind tower islocked into a substantially vertical position.
 17. A mobile tiltingframe for use in connection with a wind tower comprising: (a) wheels tomove the frame into a position proximate to the wind tower; (b) a majorgin pole having a longitudinal axis and a minor gin pole having alongitudinal axis, wherein the longitudinal axis of the minor gin poleis at an angle relative to the longitudinal axis of the major gin poleof from about 45 to about 120 degrees; (c) at least one support cableconnecting the major gin pole and the minor gin pole; and (d) at leastone tilting cable to connect or disconnect the tilting frame to the windtower.
 18. A method of lowering an erected wind tower, the wind towercomprising an elongated support structure, a turbine, and at least oneblade on a surface, the support structure being attached to afoundation, the method comprising the steps of: (a) moving a mobiletilting frame proximate to the foundation, the tilting frame comprisinga major gin pole having a longitudinal axis and a minor gin pole havinga longitudinal axis, the tilting frame having a first support cableconnecting the major and minor gin poles; (b) connecting the minor ginpole to an anchor with a second support cable; (c) tilting the tiltingframe so that the major gin pole is substantially vertical and whereinthe longitudinal axis of the minor gin pole is at an angle relative tothe longitudinal axis of the major gin pole, and (d) securing at leastone tilting cable to the major gin pole and the tower support structureand thereafter pivoting at least a portion of the wind tower to asubstantially horizontal orientation using the tilting frame.
 19. Themethod of claim 18 comprising reusing the tilting frame to lower anothererected wind tower.
 20. The method of claim 18, wherein in step (a) thelongitudinal axis of the minor gin pole is at an angle relative to thelongitudinal axis of the major gin pole of from about 45 to about 120degrees.